class Base1 {

    private int x;
    private int y;

    public Base1(int x, int y) {
        this.x = x;
        this.y = y;
    }

    public int getX() {
        return x;
    }

    public int getY() {
        return y;
    }

}
class Sub extends Base1 {

    private int z;

    public Sub(int x, int y, int z) {
        //write your code here
        super(x,y);//帮助父类进行初始化
        this.z = z;//给z进行初始化
    }

    public int getZ() {
        return z;
    }

    public int calculate() {
        return super.getX() * super.getY() * this.getZ();
    }

}
public class Main {
}
